'Worsening air quality can escalate crime rates'

The city’s growing air pollution is not only affecting health but will also escalate crime rates while impeding cognitive ability, scientists have warned.

“Studies have shown that suspended particulate matter (SPM) of 2.5u, which is 3% the size of a hair, and composed primarily of sulphates, nitrates, ammonia, sodium chloride and black carbon, affects the endocrine system, impairing judgment, increasing the possibility of violence,” said Professor Dr H Paramesh, a pulmonologist and environmental scientist at the Indian Institute of Science (IISc).

Speaking at the sidelines of a discussion on Air Pollution on Tuesday, he added that asthma and other respiratory diseases in Bengaluru had spiked from nearly zero percent in 1979 to 29.5% in 1999, before settling at 28% in 2016 –reflecting growing pollution levels.

But while increased urbanisation boosts pollutants, studies have shown how better infrastructure in a metropolis can actually mitigate the effect. Figures released by the Karnataka State Pollution Control Board shows the metro rail has led to nearly a 13.3% drop in PM 2.5 particulates in the city’s east and west areas. One-way roads in the city also caused a 28% decline.

Traffic policemen, it turned out, were some of the first and inadvertent guinea pigs for a 2002 IISc study establishing the connection between respiratory diseases and air pollutants.

Over 26% of traffic policemen developed an asthma problem, as opposed to 14% of regular policemen.

The study also showed that the further a person lived from the centre of Bengaluru, the less chance he or she had of developing a respiratory disease.

“A person living 20 kilometers from the centre of the city has a 50% less chance of developing asthma,” Dr Paramesh said.

Professor Dr Viraj Kumar, a visiting professor at the Divecha Centre for Climate Change, said there is also a clear link between bad air and IQ, which Chinese scientists confirmed last year through studies involving 31,959 people within a taluk-sized territory.

“What the study found was that the longer a person is exposed to air pollutants, the sharper the decline in mental ability,” Professor Kumar said, adding that females fared better than males to the effects of pollutants and youngsters fared better than the elderly.

“A male with 3 years of exposure to air pollutants suffered a 17% drop in cognitive ability, while females suffered a 12% drop,” he added.

Study's findings

A paper co-authored in January by Professor A R Ravishankara of Colorado State University found:

*About 60% of the estimated 1.1 million annual premature deaths from PM 2.5 in India occurred due to anthropogenic pollutants emitted from sources where premature mortality occurred.

* 19% of it from transport of pollutants from other areas within India

*16% from pollutants originating outside national borders

*4% from natural PM 2.5 sources